The present invention relates to a hydroponic growing system and particularly to a fully integrated hydroponic process and apparatus which utilizes a universally available, feed-quality barley seed or other suitable seed to produce a young barley grass product for animal feed.
Hydroponics is the art of growing plants without soil and has been practised for many years. Hydroponic systems for growing grain and legume seed to a sprouted grass crop in a controlled environment has been practised in over 10 known applications over the last 40 years. The commercial success of these systems has been limited, though it has been clearly demonstrated that high-quality plants can be produced in a very short period of time using a controlled hydroponic system.
Generally, controlled hydroponic systems for this type of application consists of a controlled environmental enclosure in which the grain is germinated and grown on either racked trays or a moving mat type system. Most of these applications included some type of air conditioning and distribution system, a water supply and irrigation system and a controlled artificial or solar light source.
In U.S. Pat. No. 2,928,211 to I. Z. Martin, issued Mar. 15, 1960 and titled xe2x80x9cHydroponic Apparatus,xe2x80x9d there is described a cabinet with a structure for supporting trays inside the cabinet. Water and nutrients are supplied to the trays through a spray system. An array of fluorescent lights illuminate the growing plant material in the trays. An air handling system includes a heat pump and heat exchanger with thermostatic controls and blowers.
U.S. Pat. No. 3,458,951 to I. Z. Martin, issued Aug. 5, 1969 and titled xe2x80x9cHydroponic Grass Unit,xe2x80x9d describes a larger controlled environmental chamber for use on farms as a barley grass production chamber. The inside chamber is insulated and temperature, humidity, light, ventilation and irrigation are carefully controlled. The growing trays are in a fixed slopped rack to promote drainage toward the rear of the enclosure.
U.S. Pat. No. 3,807,088, issued Apr. 30, 1974 and titled xe2x80x9cControlled Environmental Hydroponic System,xe2x80x9d shows a translucent building in which plants are arranged in longitudinally extended growing beds. The temperature and humidity within the building is controlled with a spray apparatus utilized to apply a fine mist over the growing plants when the sunlight becomes excessively intense.
U.S. Pat. No. 3,284,948, titled xe2x80x9cContinuous Hydroponic System,xe2x80x9d describes a system of operation in a controlled atmosphere which includes multi-layered, flexible open-mesh belts which serve as continuous growing beds. A seed hopper deposits grain in a uniform depth onto the moving belt. The seed is watered as the belt slowly moves from the seed input to the harvest side where the plant roots are stripped from the belt for use as feed.
U.S. Pat. No. 4,068,405 to Campbell et al, titled xe2x80x9cAutomatic Plant Food Production,xe2x80x9d describes a controlled environment for growing plants. The enclosure has a plurality of artificial lights positioned over the growing region. Planting trays are mounted for automatic or controlled movement past the light sources, then to a work area for planting, cultivating, crop management and harvesting.
U.S. Pat. No. 5,073,401 to L. D. Mohr, titled xe2x80x9cAutomatic Hydroponic Growing System,xe2x80x9d describes a sheet seed structure primarily for use in hydroponic systems. This pre-manufactured seed sheet is a substrate of biodegradable and digestible material such as cellulose and contains sterilized seed charged with a biologically active material. Pre-cut sheet is removed from a package and placed in a controlled growing chamber.
The U.S. Pat. No. 3,458,951 aforementioned was one of the first applications of a hydroponic barley grass factory designed as a walk-in plant capable of producing 2,000 pounds of seven day old barley grass per day.
Most of the known systems were plagued by either equipment failure, bacterial growth and/or material failure. A combination of these led to high maintenance and frequent system crashing. Most of these systems failed in a matter of months for one or a combination of the following:
Material Failurexe2x80x94The constant subjection of high humidity, air movement, intense lighting, heat generation from the growing beds and the use of chlorine and nutrients affected the application of many materials. Generally, operational failures occurred in a variety of coated carbon steels, aluminum alloys and elastomers. These failures occurred in walls and floors, particularly around joints and seams, in the growing trays and racking system, in the air ducting system, and particularly with the use of any mechanical apparatus in the growing chamber. The first units were applications of a slow-moving conveyor belt bed that took 7 days to move the 20 or 30 feet to harvest. Motors and chains were impossible to maintain in such a constant intense environment.
Germinationxe2x80x94Most of these units gave no consideration to seed germination. The seed was either metered onto a belt or scooped directly into trays, where it germinated and grew over a 7-day cycle. In order to insure a high germination rate and high barley grass yield, a xe2x80x9cseed-qualityxe2x80x9d barley had to be used for feed stock instead of the more globally available xe2x80x9cfeed-qualityxe2x80x9d seed. This led to production inefficiencies which were not acceptable in most agricultural applications.
Nutrients and Chlorinexe2x80x94Because most prior applications had no germination apparatus, nutrients were used to boost early-stage growth in order to achieve the sevenfold weight gain in 7 days as achieved without nutrients under ideal laboratory conditions. A combination of subsystem failures often brought on the rapid fungal growth in the chamber. Chlorine was introduced into several of these operating systems, creating other problems to the overall system operation.
Lightingxe2x80x94In order to intensity the operations of most systems, the growing beds were stacked and the lighting source was mounted in the walls on one or both sides of the chamber in order to illuminate all growing levels. The standard use of fluorescent tubes with ballasts or other bulbs with ballasts caused maintenance problems because of the difficult access to the walls behind the layered racking system. Sealing and resealing against moisture was a severe problem associated with most applications. Some units have employed a passive solar wall to avoid electrical expense and associated maintenance problems. These gains are lost in production control and output.
Air Handling and Treatmentxe2x80x94Most of the prior are applications relied on standard packaged, externally mounted HVAC units to control the growing chamber temperature. Unfortunately, these units were designed for supplying heated or cooled air on demand, and not the high humidity inherent in growing rooms designed for applications in extreme external conditions. Many failures also occurred because of wrong material selection for internal air ducting equipment. Different types of heat exchangers and humidity control devices have been tried with the inherent loss of overall process control. Some systems have added carbon dioxide to the air flow in order to increase production.
Water Filtration and Treatmentxe2x80x94Most of the prior art makes little or no mention of a comprehensive water management system. Of course, most of the system operational balance depends on a water source free from bacteria which could later cause and aggravate fungal and mold problems.
High production growing rooms demand continual operation, with a low daily operational time to harvest and seed and limited maintenance time.
It is a feature of the present invention to provide a self-contained hydroponic growing enclosure for the fabrication of animal feed grass and which substantially overcomes the disadvantages of the above-mentioned prior art.
Another feature of the present invention is to provide a method of hydroponic growing animal feed grass in an out-of-doors enclosure and independent of outside climatic conditions.
Another feature of the present invention is to provide a self-contained hydroponic growing enclosure which is modular in concept and designed for factory or field assembly by simple mechanical tools.
Another feature of the present invention is to provide a self-contained hydroponic growing enclosure having a racking system which utilizes a gravity feed roller system for displacing the feed trays on a daily basis and which is easy to use for loading or unloading.
Another feature of the present invention is to provide a self-contained hydroponic growing enclosure wherein the water feed system, as well as the air handling system and feed germination system, are automatically controlled.
According to the above features, from a broad aspect, the present invention provides a self-contained hydroponic growing enclosure for the fabrication of animal feed grass from seed and independent of outside climatic conditions. The growing enclosure comprises a seed grain storage means located in a control compartment section of the enclosure and isolated from a growing and harvest compartment section. Conveyor means is provided to supply seeds from the storage means to a germination tank located in the growing and harvest compartment. The germination tank has bacteria-suppressing means. A racking system is provided in the growing and harvest compartment to support a plurality of trays of germinating seed grain and growing grasses in horizontally spaced-apart growing beds. The racking system has an inlet end where the grass seeds are germinating and an outlet harvest end where the grass seeds have developed to the prerequisite grass size. Light wall units are provided on opposed sides of the racking system and dimensioned to provide light over all of the seed beds. An air handling and conditioning system having directional air outlet means is provided for circulating a continuous conditioned and filtered air flow across all of the trays in the racking system from the inlet end to the outlet harvest end. The air flow distributes carbon dioxide, generated in a section of the inlet end by the germinating seed grain, over the entire growing beds. Water supply conduit means is associated with the enclosure to connect with a pressurized water supply source. Spray means is provided to spray water over the beds. The light wall units each have a light-diffusing wall enclosure provided with light-reflecting means and an independent light housing for housing light sources and associated electrical parts. The light-reflecting means provides substantially uniform light radiation along the racking system and over the beds.
According to a further broad aspect of the present invention, there is provided a method of hydroponic growing animal feed grass in an out-of-doors enclosure and independent of outside climatic conditions. The method comprises the steps of:
(i) feeding a predetermined quantity of seed grain from a storage means to a germination tank having iodine-treated water;
(ii) germinating said seeds for a predetermined period of time;
(iii) placing a predetermined quantity of germinated seeds in a predetermined number of grass-growing trays at an inlet end of a racking system;
(iv) radiating light over beds of said trays supported in said racking system;
(v) circulating a continuous conditioned and filtered air flow across all of said trays supported in said racking system from said inlet end to an outlet harvest end; said air flow distributing carbon dioxide generated in a section of said inlet end by said germinating seed grass, over said entire growing beds; and
(vi) removing a predetermined quantity of trays of grown feed grass from said harvesting end to make room in said racking system to place the trays of step (iii).